Working Principle Of Rotor Spinning Machine

In rotor spinning, a sliver is fed into the opening unit. The fed sliver is opened into individual fibres and then the individualised fibres are reassembled, twisted and wound on a package.

Sequence of operations performed on a rotor spinning

machine is;

1.  Sliver feed

2.  Sliver opening

3.  Fiber transport into rotor

4.  Fiber collection

5.  Yarn formation

6.  Yarn take-up and winding

                              Fig : Passage of Rotor Machine

a.)        Sliver Feed :- A card or draw frame sliver is fed through a sliver guide via a feed roller (f) and feed plate (B) to a rapidly rotating opening roller (o). 

            Fig : Sliver Feed In Rotor Machine

b.)        Sliver opening: The  rotating teeth of the opening roller comb out the individual fibers from the sliver clamped between feed table and feed roller. After leaving the rotating opening roller, the fibers are fed to the fiber channel.

                           

c.)        Fibre transport to the rotor: Centrifugal forces and a vacuum in the rotor housing causes the fibres to disengage at a certain point from the opening roller and to move via the fibre channel to the inside wall of the rotor.

    

Fig : Fibre Transportation In Rotor Machine

d.)        Fiber collection in the rotor groove: The centrifugal forces in the rapidly rotating rotor cause the fibers to move from the conical rotor wall toward the rotor groove and be collected there to form a fiber ring.

   Fig : Fibre Collection At Groove In
                        Rotor Machine

e.)        Yarn formation: The rotor rotates at high speed creating a centrifugal force. To start spinning, a length of yarn already wound onto the package of the take-up mechanism is threaded through the nip line of the delivery rollers and into the draw-off tube . Because of the vacuum, the tail end of this  yarn is sucked into the rotor. The rotation of the rotor pulls the yarn end onto the part collected ribbon of fibres through the air drag and the centrifugal forces, and simultaneously inserts twist into the yarn tail. A little of this twist propagates into that part of the ribbon in contact with the yarn tail, binding it to the yarn end.

   Fig : Yarn Formation In Rotor Machine                   

f.)  Yarn Take-up and Winding: Once the yarn tail enters the rotor, the delivery rollers (K) are set in motion to pull the tail out of the rotor. The pulling action on the tail results in a peeling  of the fiber ribbon from the rotor groove. The newly formed yarn (Y) is wound up on a cheese (P) by a winding drum. A yarn stop motion interrupts material supply to the opening roller (0) when an end breaks. Capacitive or optical sensors incorporated in the yarn path record yarn faults (thick and thin places), enabling them to be cleared in limits are exceeded.